Erratum to:International Journal of Minerals,Metallurgy and Materials Volume 31,Number 1,January 2024,Page 186 https://doi.org/10.1007/s12613-023-2744-0 The original version of this article unfortunately contained thr...Erratum to:International Journal of Minerals,Metallurgy and Materials Volume 31,Number 1,January 2024,Page 186 https://doi.org/10.1007/s12613-023-2744-0 The original version of this article unfortunately contained three mistakes.The presentation of Fig.8 in original version was incorrect.The correct version is given below.展开更多
Solid-state impedance spectroscopy(SS-IS)was used to investigate the influence of structural modifications resulting from the addition of Nb2O5 on the dielectric properties and relaxation processes in the quaternary m...Solid-state impedance spectroscopy(SS-IS)was used to investigate the influence of structural modifications resulting from the addition of Nb2O5 on the dielectric properties and relaxation processes in the quaternary mixed glass former(MGF)system 35Na_(2)O–10V_(2)O_(5)–(55-x)P_(2)O_(5)–xNb_(2)O_(5)(x=0–40,mol%).The dielectric parameters,including the dielectric strength and dielectric loss,are determined from the frequency and temperature-dependent complex permittivity data,revealing a significant dependence on the Nb2O5 content.The transition from a predominantly phosphate glass network(x<10,region I)to a mixed niobate–phosphate glass net-work(10≤x≤20,region II)leads to an increase in the dielectric parameters,which correlates with the observed trend in the direct-cur-rent(DC)conductivity.In the predominantly niobate network(x≥25,region III),the highly polarizable nature of Nb5+ions leads to a fur-ther increase in the dielectric permittivity and dielectric strength.This is particularly evident in Nb-40 glass-ceramic,which contains Na_(13)Nb_(35)O_(94) crystalline phase with a tungsten bronze structure and exhibits the highest dielectric permittivity of 61.81 and the lowest loss factor of 0.032 at 303 K and 10 kHz.The relaxation studies,analyzed through modulus formalism and complex impedance data,show that DC conductivity and relaxation processes are governed by the same mechanism,attributed to ionic conductivity.In contrast to glasses with a single peak in frequency dependence of imaginary part of electrical modulus,M″(ω),Nb-40 glass-ceramic exhibits two distinct contributions with similar relaxation times.The high-frequency peak indicates bulk ionic conductivity,while the additional low-fre-quency peak is associated with the grain boundary effect,confirmed by the electrical equivalent circuit(EEC)modelling.The scaling characteristics of permittivity and conductivity spectra,along with the electrical modulus,validate time-temperature superposition and demonstrate a strong correlation with composition and modification of the glass structure upon Nb_(2)O_(5) incorporation.展开更多
The formation and evolution characteristics of bcc phase during the isothermal relaxation processes for supercooled-liquid and amorphous Pb were investigated by molecular dynamics simulation and cluster-type index met...The formation and evolution characteristics of bcc phase during the isothermal relaxation processes for supercooled-liquid and amorphous Pb were investigated by molecular dynamics simulation and cluster-type index method （CTIM）. It is found that during the relaxation process, the formation and evolution of bcc phase are closely dependent on the initial temperature and structure. During the simulation time scale, when the initial temperature is in the range of supercooled liquid region, the bcc phase can be formed and kept a long time; while it is in the range of glassy region, the bcc phase can be formed at first and then partially transformed into hcp phase; when it decreases to the lower one, the hcp and fcc phases can be directly transformed from the glassy structure without undergoing the metastable bcc phase. The Ostwald＇s ＂step rule＂ is impactful during the isothermal relaxation process of the supercooled and glassy Pb, and the metastable bcc phase plays an important role in the precursor of crystallization.展开更多
Multi-scales relaxation processes of short fiber of a nematic liquid crystalline copolymer(LCP)in polycarbonate matrix were investigated.First,the structure relaxation of LCP was studied by rheology.The relaxation spe...Multi-scales relaxation processes of short fiber of a nematic liquid crystalline copolymer(LCP)in polycarbonate matrix were investigated.First,the structure relaxation of LCP was studied by rheology.The relaxation spectrum of the nematic liquid crystalline copolymer at 295℃was calculated from the combined dynamic modulus.There are three kinds of relaxation mechanisms for nematic liquid crystalline copotymer:the relaxation of chain orientation,the relaxation of deformed polydomains and the coalescence of pol...展开更多
This paper is devoted to the existence results for a class of neutral abstract fractional differential equations involving the composite relaxation process.Based on the Laplace transform,the semigroup theory and the W...This paper is devoted to the existence results for a class of neutral abstract fractional differential equations involving the composite relaxation process.Based on the Laplace transform,the semigroup theory and the Wright functions,we first introduce a definition of mild solutions to the considered problem.By means of the noncompactness of measure and the fixed point technique,we establish existence criteria of solutions.Finally,an example is presented to illustrate our main result.展开更多
To research the correlation between vibrational energy transition rates and acoustic relaxation processes in excitable gases, the vibrational relaxation theory provided by Tanczos [J. Chem. Phy3. 25, 439 （1956）] is ...To research the correlation between vibrational energy transition rates and acoustic relaxation processes in excitable gases, the vibrational relaxation theory provided by Tanczos [J. Chem. Phy3. 25, 439 （1956）] is applied to calculate the energy transition rates of Vibrational- Vibrational （V-V） and Vibrational-Translational （V-T） energy transfer in gas mixtures. The results of calculation for the multi-relaxation processes in various gas mixtures, consisting of carbon dioxide, methane, chlorine, nitrogen, and oxygen at room temperature, demonstrate that the acoustic energy stagnated in every vibrational mode is coupled with each other through V-V energy exchanges. The vibrational excitation energy will relax through the V-T de-excitation path of the lowest mode because of its fastest V-T transition rate, resulting in that only one absorption peak can be measured for most of excitable gas mixtures. Thus, an effective model is provided to analyze how the vibrational energy transition rates affect the characteristics of acoustic relaxation processes and acoustic propagation in excitable gas mixtures.展开更多
The study presents the experimental results of measurements of the relaxation time of cryogels formed from various colloid-dispersed systems based on a poly(vinyl alcohol) aqueous solution.It is shown that the value o...The study presents the experimental results of measurements of the relaxation time of cryogels formed from various colloid-dispersed systems based on a poly(vinyl alcohol) aqueous solution.It is shown that the value of relaxation time,which characterizes the relationship between the viscosity and elasticity of real bodies,describes the rheological properties of materials more objectively than the traditional assessment of their physical and mechanical characteristics only by the elasticity modulus of the samples.展开更多
By extending the concept of diffusion to the potential energy landscapes(PELs), we introduce the meansquared energy difference(MSED) as a novel quantity to investigate the intrinsic properties of supercooled liquids. ...By extending the concept of diffusion to the potential energy landscapes(PELs), we introduce the meansquared energy difference(MSED) as a novel quantity to investigate the intrinsic properties of supercooled liquids. MSED can provide a clear description of the “energy relaxation” process on a PEL. Through MSED analysis, we have obtained a characteristic time similar to that derived from structure analysis, namely τ_(α)^(*).Further, we establish a connection between MSED and the feature of PELs, providing a concise and quantitative description of PELs. The relaxation behavior of energy has been found to follow a stretched exponential form.As the temperature decreases, the roughness of the accessible PEL changes significantly around a characteristic temperature T_(x), which is 20% higher than the glass transition temperature T_(g) and is comparable to the critical temperature of the mode-coupling theory. More importantly, one of the PEL parameters is closely related to the Adam–Gibbs configurational entropy. The present research, which directly links the PEL to the relaxation process, provides avenues for further research of glasses.展开更多
Ce-substituted lithium ferrite, Li0.5CexFe2.5-x04 （x = 0, 0.05 and 0.1 ） compositions were synthesized from metal nitrates and citric acid by the solution combustion process by keeping the oxidizer to fuel ratio at ...Ce-substituted lithium ferrite, Li0.5CexFe2.5-x04 （x = 0, 0.05 and 0.1 ） compositions were synthesized from metal nitrates and citric acid by the solution combustion process by keeping the oxidizer to fuel ratio at unity. The thermal decomposition process was investigated by thermogravimetry-differential thermal analysis, which showed a stable phase formation above 600 ℃. The phase composition and molecular bonding of Li0.5CexFe2.5_x04 were characterized by X-ray powder diffraction analysis and Fourier transform infrared spectroscopy, respectively. An extensive study of electrical relaxation process has been represented with impedance and modulus as a function of frequency at different temperatures. The activation energy obtained from both the formalisms was found to be equal within the error. The dc conductivity and hopping frequency were thermally activated and their activation energies were found to be in the range of 0.69-0.64 eV for x = 0.05. The scaling of modulus and impedance were used to understand the electrical relaxation behaviour of the compositions and they suggest the time temperature superposition principle.展开更多
The newly designed high performance tested steel was prepared by the process of vacuum induction furnace smelting and forging. According to the ideas of online relaxation and quenching intercritieal quenching-temperi...The newly designed high performance tested steel was prepared by the process of vacuum induction furnace smelting and forging. According to the ideas of online relaxation and quenching intercritieal quenching-tempering （Q- L-T） process, effects of offline relaxation process on microstructure and mechanical properties of the tested steel were investigated. Offline results process was simulated using the MMS-300 thermal simulation testing apparatus and heat treating furnace. The results show that the microstructures are composed of bainite and martensite when the specimens are quenched in the austenite region. Once the specimens are ai〉cooled into the dual phase region, ferrite and granular bainite start to form. In the relaxation process, fine Nb（C, N） carbonitrides are precipitated first and then grow and coarsen. The microstructure is affected by process and determines mechanical properties. The Vickers hardness and yield strength （YS） first rise then fall when the relaxation temperature drops in austenite region, and then decline dramatically in dual phase region. When the relaxation time is 20 s, the tensile strength reaches the peak （1034 MPa）, and at that time YS is 872 MPa, elongation is 17.7% and Charpy V-notch impact energy is 171 J at -20℃. When the relaxation time increases to 100 s, the yield and tensile strengths are 750 and 934 MPa respectively, elon- gation is 18.6% and Charpy V-notch impact energy is 165 J at -20℃.展开更多
The post-seismic horizontal and vertical deformations following the 2008 Ms8.0 Wenchuan earth- quake are inferred from GPS and precise leveling data. The post-seismic relaxation process is measured using GPS data from...The post-seismic horizontal and vertical deformations following the 2008 Ms8.0 Wenchuan earth- quake are inferred from GPS and precise leveling data. The post-seismic relaxation process is measured using GPS data from campaign stations located around the Longmenshan fault, and the derived decay time constant is 12 days. The evolution of the post-seismic vertical deformation is obtained from precise leveling data measured near the surface rupture. The results demonstrate that the hanging wall is uplifting and the foot wall is subsi- ding. The amplitude of the post-seismic deformation is lower than that of the co-seismic deformation. The re- gion with the largest post-seismic displacement is located on the leveling route between Maoxian and Beichuan on the hanging wall.展开更多
The degradation process of lithium-ion batteries is intricately linked to their entire lifecycle as power sources and energy storage devices,encompassing aspects such as performance delivery and cycling utilization.Co...The degradation process of lithium-ion batteries is intricately linked to their entire lifecycle as power sources and energy storage devices,encompassing aspects such as performance delivery and cycling utilization.Consequently,the accurate and expedient estimation or prediction of the aging state of lithium-ion batteries has garnered extensive attention.Nonetheless,prevailing research predominantly concentrates on either aging estimation or prediction,neglecting the dynamic fusion of both facets.This paper proposes a hybrid model for capacity aging estimation and prediction based on deep learning,wherein salient features highly pertinent to aging are extracted from charge and discharge relaxation processes.By amalgamating historical capacity decay data,the model dynamically furnishes estimations of the present capacity and forecasts of future capacity for lithium-ion batteries.Our approach is validated against a novel dataset involving charge and discharge cycles at varying rates.Specifically,under a charging condition of 0.25 C,a mean absolute percentage error(MAPE)of 0.29%is achieved.This outcome underscores the model's adeptness in harnessing relaxation processes commonly encountered in the real world and synergizing with historical capacity records within battery management systems(BMS),thereby affording estimations and prognostications of capacity decline with heightened precision.展开更多
The laser-induced damage threshold(LIDT)of optical elements is a critical limitation in advancing nextgeneration spaceborne laser technologies.Transient mechanisms in multiple-pulse damage dynamics have been recognize...The laser-induced damage threshold(LIDT)of optical elements is a critical limitation in advancing nextgeneration spaceborne laser technologies.Transient mechanisms in multiple-pulse damage dynamics have been recognized,but significant gaps remain in understanding these processes.In this study,we introduce a practice time interval(Δt_(p))-dependent damage metric.Using a double-pulse double-probe experimental configuration,we systematically examine the double-pulse damage dynamics and relaxation process.The first pulse induces localized modifications that initiate a relaxation process,accumulating material damage caused by the subsequent pulse.Our results show that this relaxation lasts~500 ns for surface damage and is on a several millisecond scale for bulk damage.The second pulse induces more pronounced modifications and damage whenΔt_(p)is less than100 ns,dominated by nonlinear phenomena like multiphoton absorption due to temporally overlapping pulses.Conversely,forΔt_(p)>100 ns,thermal accumulation via phonon relaxation predominates.Additionally,the critical energy density for damage correlates positively with LIDT asΔt_(p)increases,reflecting the reduced thermal and mechanical stress influence.These findings highlight the dynamic competition between nonlinear and thermal effects in multiple-pulse laser interactions,providing practical strategies for designing optical components with high damage thresholds and developing high-performance optical systems.展开更多
In the present paper, random-choice method (RCM) and second-order GRP difference method, which are high resolution methods used for pure gas flows with shocks, are extended and employed to study the problem of one-dim...In the present paper, random-choice method (RCM) and second-order GRP difference method, which are high resolution methods used for pure gas flows with shocks, are extended and employed to study the problem of one-dimensional unsteady two-phase flows. The two-phase shock wave and the flow field behind it in a dusty gas shock tube are calculated and the time-dependent change of the flow parameters for the gas and particle phase are obtained. The numerical results indicate that both the two methods can give the relaxation structure of the two-phase shocks with a sharp discontinuous front and that the GRP method has the advantages of less time-consuming and higher accuracy over the RCM method.展开更多
Radar cross-section (RCS) measurement with the near-field electromagnetic wave illumination of a target has been proved to be practical. The existing methods employ the multiplefrequency angular-diversity (MFAD) techn...Radar cross-section (RCS) measurement with the near-field electromagnetic wave illumination of a target has been proved to be practical. The existing methods employ the multiplefrequency angular-diversity (MFAD) technique, whereas this paper considers the single-frequency angular-diversity (SFAD) technique. The paper takes into account the scattering center modeling and the limitation of higher sidelobes in reconstructing images in the SFAD technique compared to the MFAD technique. A method of combining the SFAD technique with the RELAX approach is presented for the high-resolution extraction of scattering centers on a target. The proposed method offers an excellent RCS recovery, which is validated by numerical results.展开更多
Metallomesogens Ln（bta）3L2 （Ln^3＋： La^3＋, Eu^3＋, and Ho^3＋; bta： benzoyltrifluoroacetonate; L： Schiff base） were prepared. Photoacoustic （PA） spectroscopy was used to study physicochemical properties of t...Metallomesogens Ln（bta）3L2 （Ln^3＋： La^3＋, Eu^3＋, and Ho^3＋; bta： benzoyltrifluoroacetonate; L： Schiff base） were prepared. Photoacoustic （PA） spectroscopy was used to study physicochemical properties of the liquid crystalline metal complexes. In the region of ligand absorption, PA intensity increases for Eu（bta）3L2, La（bta）3L2, and Ho（bta）3L2, in that order. It is found that the PA intensity of the ligand bears a relation to the intramolecular energy transfer process. For the first time, phase transitions of Eu（bta）3L2 from glass state to smectic A （SmA） phase and SmA phase to isotropic liquid are monitored by PA and fluorescence （FL） spectroscopy from two aspects： nonradiative and radiative transitions. The results show that PA technique may serve as a new tool for investigating the spectral properties and phase transitions of liquid crystals containing metal ions.展开更多
This paper investigates the electron-vibrational（e-V）energy exchange in nitrogencontaining plasma,which is very efficient in the case of gas discharge and high speed flow.Based on Harmonic oscillator approximation a...This paper investigates the electron-vibrational（e-V）energy exchange in nitrogencontaining plasma,which is very efficient in the case of gas discharge and high speed flow.Based on Harmonic oscillator approximation and the assumption of the e-V relaxation through a continuous series of Boltzmann distributions over the vibrational states,an analytic approach is derived from the proposed scaling relation of e-V transition rates.A full kinetic model is then investigated by numerically solving the state-to-state master equation for all vibrational levels.The analytical approach leads to a Landau-Teller（LT）-type equation for relaxation of vibrational energy,and predicts the relaxation time on the right order of magnitude.By comparison with the kinetic model,the LT-type equation is valid in typical electron temperatures in gas discharge.However,the analytical approach is not capable of describing the vibrational distribution function during the e-V process in which a full kinetic model is required.展开更多
The main aim of this research is to investigate the effect of salt concentration on the dielectric properties （AC （CrAC）, permittivity （d）, dielectric loss （d＇）, and dielectric relaxation process） and melting...The main aim of this research is to investigate the effect of salt concentration on the dielectric properties （AC （CrAC）, permittivity （d）, dielectric loss （d＇）, and dielectric relaxation process） and melting behavior of polyethylene oxide （PEO）/CdC12 complexes. The dielectric study was carried out over a frequency range 10-335 kHz and a temperature range 25--45~C. The AC conductivity, permittivity and dielectric loss of the PEO/CdC12 complexes increase with increasing salt concentration and temperature. Also, it was found that the addition of CdC12 salt to PEO host reduced the melting temperature of PEO host. Dielectric results reveal that the relaxation process of these complexes is due to viscoelastic relaxation or non-Debye relaxation at room temperature. Additionally, it was found that relaxation behavior remained viscoelastic at different temperatures and salt concentrations.展开更多
A transient molecular network model is built to describe the non- linear viscoelasticity of polymers by considering the effect of entanglement loss and regeneration on the relaxation of molecular strands. It is an ext...A transient molecular network model is built to describe the non- linear viscoelasticity of polymers by considering the effect of entanglement loss and regeneration on the relaxation of molecular strands. It is an extension of previous network theories. The experimental data on three thermoplastic polymers (ABS, PVC and PA6) obtained under various loading conditions are used to test the model. Agreement between the theoretical and experimental curves shows that the suggested model can describe successfully the relaxation behavior of the thermoplastic polymers under different loading rates by using relatively few relaxation modes. Thus the mi- cromechanism responsible for strain-rate dependence of relaxation process and the origin of nonlinear viscoelasticity may be disclosed.展开更多
文摘Erratum to:International Journal of Minerals,Metallurgy and Materials Volume 31,Number 1,January 2024,Page 186 https://doi.org/10.1007/s12613-023-2744-0 The original version of this article unfortunately contained three mistakes.The presentation of Fig.8 in original version was incorrect.The correct version is given below.
文摘Solid-state impedance spectroscopy(SS-IS)was used to investigate the influence of structural modifications resulting from the addition of Nb2O5 on the dielectric properties and relaxation processes in the quaternary mixed glass former(MGF)system 35Na_(2)O–10V_(2)O_(5)–(55-x)P_(2)O_(5)–xNb_(2)O_(5)(x=0–40,mol%).The dielectric parameters,including the dielectric strength and dielectric loss,are determined from the frequency and temperature-dependent complex permittivity data,revealing a significant dependence on the Nb2O5 content.The transition from a predominantly phosphate glass network(x<10,region I)to a mixed niobate–phosphate glass net-work(10≤x≤20,region II)leads to an increase in the dielectric parameters,which correlates with the observed trend in the direct-cur-rent(DC)conductivity.In the predominantly niobate network(x≥25,region III),the highly polarizable nature of Nb5+ions leads to a fur-ther increase in the dielectric permittivity and dielectric strength.This is particularly evident in Nb-40 glass-ceramic,which contains Na_(13)Nb_(35)O_(94) crystalline phase with a tungsten bronze structure and exhibits the highest dielectric permittivity of 61.81 and the lowest loss factor of 0.032 at 303 K and 10 kHz.The relaxation studies,analyzed through modulus formalism and complex impedance data,show that DC conductivity and relaxation processes are governed by the same mechanism,attributed to ionic conductivity.In contrast to glasses with a single peak in frequency dependence of imaginary part of electrical modulus,M″(ω),Nb-40 glass-ceramic exhibits two distinct contributions with similar relaxation times.The high-frequency peak indicates bulk ionic conductivity,while the additional low-fre-quency peak is associated with the grain boundary effect,confirmed by the electrical equivalent circuit(EEC)modelling.The scaling characteristics of permittivity and conductivity spectra,along with the electrical modulus,validate time-temperature superposition and demonstrate a strong correlation with composition and modification of the glass structure upon Nb_(2)O_(5) incorporation.
基金Projects (50831003, 50571037) supported by the National Natural Science Foundation of China
文摘The formation and evolution characteristics of bcc phase during the isothermal relaxation processes for supercooled-liquid and amorphous Pb were investigated by molecular dynamics simulation and cluster-type index method （CTIM）. It is found that during the relaxation process, the formation and evolution of bcc phase are closely dependent on the initial temperature and structure. During the simulation time scale, when the initial temperature is in the range of supercooled liquid region, the bcc phase can be formed and kept a long time; while it is in the range of glassy region, the bcc phase can be formed at first and then partially transformed into hcp phase; when it decreases to the lower one, the hcp and fcc phases can be directly transformed from the glassy structure without undergoing the metastable bcc phase. The Ostwald＇s ＂step rule＂ is impactful during the isothermal relaxation process of the supercooled and glassy Pb, and the metastable bcc phase plays an important role in the precursor of crystallization.
基金This work was financially supported by the National Natural Science Foundation of China(Nos. 20174024,20204007 and 50290090).
文摘Multi-scales relaxation processes of short fiber of a nematic liquid crystalline copolymer(LCP)in polycarbonate matrix were investigated.First,the structure relaxation of LCP was studied by rheology.The relaxation spectrum of the nematic liquid crystalline copolymer at 295℃was calculated from the combined dynamic modulus.There are three kinds of relaxation mechanisms for nematic liquid crystalline copotymer:the relaxation of chain orientation,the relaxation of deformed polydomains and the coalescence of pol...
基金Supported by the Guangxi Science and Technology base and Talent Project(AD23026249,AD22080047).
文摘This paper is devoted to the existence results for a class of neutral abstract fractional differential equations involving the composite relaxation process.Based on the Laplace transform,the semigroup theory and the Wright functions,we first introduce a definition of mild solutions to the considered problem.By means of the noncompactness of measure and the fixed point technique,we establish existence criteria of solutions.Finally,an example is presented to illustrate our main result.
基金supported by the National Natural Science Foundation of China(61461008,61371139,61571201,61540051)the China Scholarship Council Project(201708525058)+1 种基金the National Science Foundation of Guizhou Province,China(Qian Ke He J Zi[2015]2065),Qian Ke He LH Zi[2014]7361)the Recruitment Program of Guizhou Institute of Technology(XJGC20140601,XJGC20150107)
文摘To research the correlation between vibrational energy transition rates and acoustic relaxation processes in excitable gases, the vibrational relaxation theory provided by Tanczos [J. Chem. Phy3. 25, 439 （1956）] is applied to calculate the energy transition rates of Vibrational- Vibrational （V-V） and Vibrational-Translational （V-T） energy transfer in gas mixtures. The results of calculation for the multi-relaxation processes in various gas mixtures, consisting of carbon dioxide, methane, chlorine, nitrogen, and oxygen at room temperature, demonstrate that the acoustic energy stagnated in every vibrational mode is coupled with each other through V-V energy exchanges. The vibrational excitation energy will relax through the V-T de-excitation path of the lowest mode because of its fastest V-T transition rate, resulting in that only one absorption peak can be measured for most of excitable gas mixtures. Thus, an effective model is provided to analyze how the vibrational energy transition rates affect the characteristics of acoustic relaxation processes and acoustic propagation in excitable gas mixtures.
文摘The study presents the experimental results of measurements of the relaxation time of cryogels formed from various colloid-dispersed systems based on a poly(vinyl alcohol) aqueous solution.It is shown that the value of relaxation time,which characterizes the relationship between the viscosity and elasticity of real bodies,describes the rheological properties of materials more objectively than the traditional assessment of their physical and mechanical characteristics only by the elasticity modulus of the samples.
基金supported by the National Key Research and Development Program of China (Grant No. 2022YFA1404603)by the National Natural Science Foundation of China (Grant Nos. 12274127 and 12188101)。
文摘By extending the concept of diffusion to the potential energy landscapes(PELs), we introduce the meansquared energy difference(MSED) as a novel quantity to investigate the intrinsic properties of supercooled liquids. MSED can provide a clear description of the “energy relaxation” process on a PEL. Through MSED analysis, we have obtained a characteristic time similar to that derived from structure analysis, namely τ_(α)^(*).Further, we establish a connection between MSED and the feature of PELs, providing a concise and quantitative description of PELs. The relaxation behavior of energy has been found to follow a stretched exponential form.As the temperature decreases, the roughness of the accessible PEL changes significantly around a characteristic temperature T_(x), which is 20% higher than the glass transition temperature T_(g) and is comparable to the critical temperature of the mode-coupling theory. More importantly, one of the PEL parameters is closely related to the Adam–Gibbs configurational entropy. The present research, which directly links the PEL to the relaxation process, provides avenues for further research of glasses.
基金Financial support from the UGC-SAP F.530/15/DRS/2009
文摘Ce-substituted lithium ferrite, Li0.5CexFe2.5-x04 （x = 0, 0.05 and 0.1 ） compositions were synthesized from metal nitrates and citric acid by the solution combustion process by keeping the oxidizer to fuel ratio at unity. The thermal decomposition process was investigated by thermogravimetry-differential thermal analysis, which showed a stable phase formation above 600 ℃. The phase composition and molecular bonding of Li0.5CexFe2.5_x04 were characterized by X-ray powder diffraction analysis and Fourier transform infrared spectroscopy, respectively. An extensive study of electrical relaxation process has been represented with impedance and modulus as a function of frequency at different temperatures. The activation energy obtained from both the formalisms was found to be equal within the error. The dc conductivity and hopping frequency were thermally activated and their activation energies were found to be in the range of 0.69-0.64 eV for x = 0.05. The scaling of modulus and impedance were used to understand the electrical relaxation behaviour of the compositions and they suggest the time temperature superposition principle.
基金Item Sponsored by National Basic Research Program(973Program)of China(2010CB630801)
文摘The newly designed high performance tested steel was prepared by the process of vacuum induction furnace smelting and forging. According to the ideas of online relaxation and quenching intercritieal quenching-tempering （Q- L-T） process, effects of offline relaxation process on microstructure and mechanical properties of the tested steel were investigated. Offline results process was simulated using the MMS-300 thermal simulation testing apparatus and heat treating furnace. The results show that the microstructures are composed of bainite and martensite when the specimens are quenched in the austenite region. Once the specimens are ai〉cooled into the dual phase region, ferrite and granular bainite start to form. In the relaxation process, fine Nb（C, N） carbonitrides are precipitated first and then grow and coarsen. The microstructure is affected by process and determines mechanical properties. The Vickers hardness and yield strength （YS） first rise then fall when the relaxation temperature drops in austenite region, and then decline dramatically in dual phase region. When the relaxation time is 20 s, the tensile strength reaches the peak （1034 MPa）, and at that time YS is 872 MPa, elongation is 17.7% and Charpy V-notch impact energy is 171 J at -20℃. When the relaxation time increases to 100 s, the yield and tensile strengths are 750 and 934 MPa respectively, elon- gation is 18.6% and Charpy V-notch impact energy is 165 J at -20℃.
基金supported by the Special Earthquake Research Project Granted by the China Earthquake Administration(201208006)the National Natural Science Foundation of China(41174083,40974062)
文摘The post-seismic horizontal and vertical deformations following the 2008 Ms8.0 Wenchuan earth- quake are inferred from GPS and precise leveling data. The post-seismic relaxation process is measured using GPS data from campaign stations located around the Longmenshan fault, and the derived decay time constant is 12 days. The evolution of the post-seismic vertical deformation is obtained from precise leveling data measured near the surface rupture. The results demonstrate that the hanging wall is uplifting and the foot wall is subsi- ding. The amplitude of the post-seismic deformation is lower than that of the co-seismic deformation. The re- gion with the largest post-seismic displacement is located on the leveling route between Maoxian and Beichuan on the hanging wall.
文摘The degradation process of lithium-ion batteries is intricately linked to their entire lifecycle as power sources and energy storage devices,encompassing aspects such as performance delivery and cycling utilization.Consequently,the accurate and expedient estimation or prediction of the aging state of lithium-ion batteries has garnered extensive attention.Nonetheless,prevailing research predominantly concentrates on either aging estimation or prediction,neglecting the dynamic fusion of both facets.This paper proposes a hybrid model for capacity aging estimation and prediction based on deep learning,wherein salient features highly pertinent to aging are extracted from charge and discharge relaxation processes.By amalgamating historical capacity decay data,the model dynamically furnishes estimations of the present capacity and forecasts of future capacity for lithium-ion batteries.Our approach is validated against a novel dataset involving charge and discharge cycles at varying rates.Specifically,under a charging condition of 0.25 C,a mean absolute percentage error(MAPE)of 0.29%is achieved.This outcome underscores the model's adeptness in harnessing relaxation processes commonly encountered in the real world and synergizing with historical capacity records within battery management systems(BMS),thereby affording estimations and prognostications of capacity decline with heightened precision.
基金National Key Research and Development Program of China(2021YFB3601402)National Natural Science Foundation of China(61975153)。
文摘The laser-induced damage threshold(LIDT)of optical elements is a critical limitation in advancing nextgeneration spaceborne laser technologies.Transient mechanisms in multiple-pulse damage dynamics have been recognized,but significant gaps remain in understanding these processes.In this study,we introduce a practice time interval(Δt_(p))-dependent damage metric.Using a double-pulse double-probe experimental configuration,we systematically examine the double-pulse damage dynamics and relaxation process.The first pulse induces localized modifications that initiate a relaxation process,accumulating material damage caused by the subsequent pulse.Our results show that this relaxation lasts~500 ns for surface damage and is on a several millisecond scale for bulk damage.The second pulse induces more pronounced modifications and damage whenΔt_(p)is less than100 ns,dominated by nonlinear phenomena like multiphoton absorption due to temporally overlapping pulses.Conversely,forΔt_(p)>100 ns,thermal accumulation via phonon relaxation predominates.Additionally,the critical energy density for damage correlates positively with LIDT asΔt_(p)increases,reflecting the reduced thermal and mechanical stress influence.These findings highlight the dynamic competition between nonlinear and thermal effects in multiple-pulse laser interactions,providing practical strategies for designing optical components with high damage thresholds and developing high-performance optical systems.
文摘In the present paper, random-choice method (RCM) and second-order GRP difference method, which are high resolution methods used for pure gas flows with shocks, are extended and employed to study the problem of one-dimensional unsteady two-phase flows. The two-phase shock wave and the flow field behind it in a dusty gas shock tube are calculated and the time-dependent change of the flow parameters for the gas and particle phase are obtained. The numerical results indicate that both the two methods can give the relaxation structure of the two-phase shocks with a sharp discontinuous front and that the GRP method has the advantages of less time-consuming and higher accuracy over the RCM method.
基金the National Natural Science Foundation of China.
文摘Radar cross-section (RCS) measurement with the near-field electromagnetic wave illumination of a target has been proved to be practical. The existing methods employ the multiplefrequency angular-diversity (MFAD) technique, whereas this paper considers the single-frequency angular-diversity (SFAD) technique. The paper takes into account the scattering center modeling and the limitation of higher sidelobes in reconstructing images in the SFAD technique compared to the MFAD technique. A method of combining the SFAD technique with the RELAX approach is presented for the high-resolution extraction of scattering centers on a target. The proposed method offers an excellent RCS recovery, which is validated by numerical results.
基金This work was supported by the National Natural Science Foundation of China （No.10574073 and No.10574071）. Financial support by the K. U. Leuven （No.GOA 03/03） is gratefully acknowledged.
文摘Metallomesogens Ln（bta）3L2 （Ln^3＋： La^3＋, Eu^3＋, and Ho^3＋; bta： benzoyltrifluoroacetonate; L： Schiff base） were prepared. Photoacoustic （PA） spectroscopy was used to study physicochemical properties of the liquid crystalline metal complexes. In the region of ligand absorption, PA intensity increases for Eu（bta）3L2, La（bta）3L2, and Ho（bta）3L2, in that order. It is found that the PA intensity of the ligand bears a relation to the intramolecular energy transfer process. For the first time, phase transitions of Eu（bta）3L2 from glass state to smectic A （SmA） phase and SmA phase to isotropic liquid are monitored by PA and fluorescence （FL） spectroscopy from two aspects： nonradiative and radiative transitions. The results show that PA technique may serve as a new tool for investigating the spectral properties and phase transitions of liquid crystals containing metal ions.
基金supported by National Natural Science Foundation of China(No.11505015)the National High-Tech Research and Development Program of China(863 Program)
文摘This paper investigates the electron-vibrational（e-V）energy exchange in nitrogencontaining plasma,which is very efficient in the case of gas discharge and high speed flow.Based on Harmonic oscillator approximation and the assumption of the e-V relaxation through a continuous series of Boltzmann distributions over the vibrational states,an analytic approach is derived from the proposed scaling relation of e-V transition rates.A full kinetic model is then investigated by numerically solving the state-to-state master equation for all vibrational levels.The analytical approach leads to a Landau-Teller（LT）-type equation for relaxation of vibrational energy,and predicts the relaxation time on the right order of magnitude.By comparison with the kinetic model,the LT-type equation is valid in typical electron temperatures in gas discharge.However,the analytical approach is not capable of describing the vibrational distribution function during the e-V process in which a full kinetic model is required.
文摘The main aim of this research is to investigate the effect of salt concentration on the dielectric properties （AC （CrAC）, permittivity （d）, dielectric loss （d＇）, and dielectric relaxation process） and melting behavior of polyethylene oxide （PEO）/CdC12 complexes. The dielectric study was carried out over a frequency range 10-335 kHz and a temperature range 25--45~C. The AC conductivity, permittivity and dielectric loss of the PEO/CdC12 complexes increase with increasing salt concentration and temperature. Also, it was found that the addition of CdC12 salt to PEO host reduced the melting temperature of PEO host. Dielectric results reveal that the relaxation process of these complexes is due to viscoelastic relaxation or non-Debye relaxation at room temperature. Additionally, it was found that relaxation behavior remained viscoelastic at different temperatures and salt concentrations.
基金The project supported by the National Natural Science Foundation of China and Doctorial Fund
文摘A transient molecular network model is built to describe the non- linear viscoelasticity of polymers by considering the effect of entanglement loss and regeneration on the relaxation of molecular strands. It is an extension of previous network theories. The experimental data on three thermoplastic polymers (ABS, PVC and PA6) obtained under various loading conditions are used to test the model. Agreement between the theoretical and experimental curves shows that the suggested model can describe successfully the relaxation behavior of the thermoplastic polymers under different loading rates by using relatively few relaxation modes. Thus the mi- cromechanism responsible for strain-rate dependence of relaxation process and the origin of nonlinear viscoelasticity may be disclosed.
